Process of electric welding.



A. L. JOHNSON.

PROCESS OP ELECTRIC WELDING.

APPLICATION FILED APRA. 1912.

1,039,11. 87. f l Patented Sept. 24, 1912.

Mir/95565:' @13W CIT;

girder built up of ALBERT L. JOHNSON, 0F HAMBURG, NEW YORK.

PROCESS 0F ELECTRIC WELDING.

Spec'ication of Letters Patent.

Patented sept. 24.. 1912.

Application iled April 4, 1912. Serial No. 688,564.

To all 'whom t may concern.' y

Be it known that I, ALBERT L. JOHNSON, a citizen of the United States, and a resident of the town of Hamburg, county of Erie,V and State of New York, have invented a new and useful Process of ElectricWelding, of which the following is a specification.

. y invention relates to the welding together of two or more metal members by means of an electric current; and has for its principal objects to provide for the instantaneous welding of such members without any previous treatment thereof, to provide for the welding together of members of different thicknesses, to provide for the proper spacing of the members when the welding operation is completed, to provide for a wide spread of the welding joint, to effect economies hereinafter mentioned, and to attain various advantages..

The invention consists principally in the use of metal buttons or inserts, interposed between the members to be welded together, as hereinafter set forth.

ln theaccompanying drawing, which forms part of this specification, and wherein like symbols refer to like parts wherever they occur, Figure l is a cross section of a members welded together according to my process; Fig. 2 is a side view of the end portion of such a'girder; Fig. 3 is a detail sectional View of two metal members with a metal insert interposed between them preparatory to the welding of said elements together; Fig. l is a detail view in section showing said metal members and insert welded together; Fig. 5 is a detail sectional view illustrating an insert interposed between two metal elements of different thicknesses preparatory to the welding thereof; Fig. 6 is a detail sectionalview thereof after the welding; and Fig. 7 illustrates various forms of metal inserts showing a sectional view thereof and also an end view thereof. l

Between the metal members l and 2, which are to be welded together, is inter posed a metal button or insertl 3, said insert being positioned at the point where it is desired to weld the two members l and 2. The two members are then pressed toward each other and the electric current simultaneously applied by means of electrodes 4 and 5 in cont-act'wit-h the respective elements.

The pressure may be effected by special mechanical appliances; but, in shop practice, it is preferable to mount the electrodes on rollers and elfect the pressure thereby, t-he electrodes bearing against the outer surfaces of the respective members preferably in substantial alinement with the interposed button or insert. However, as the electric current will pass through the insert regardless of the'points of application of the electrodes, it is notessential'that the electrodes should be in alinement with the insert; and this fact widens theiield of utility of the process. For instance, it enables the process to be used in securing the metal members of the framework ofa building while the work is in progress. ln such case,the cross sectional area of the metal building element is so large that the increase of electrical resistance by reason -of the electrode being applied at a distance from the metal insert is of little significance; but inthe case of thin metal elements, such increase of resistance involves waste of current and possible injury of the element.

As indicated in t-he drawing, the area of the electrodes in contact with the members to be welded is* preferably considerably larger than the area in contact with the button or insert. In consequence' of the arrangement and conditions above stated, the electric current is localized on the insert and the port-ions of the members 1 and 2 in contact with said insert or immediately adjacent thereto. The current thus localized almost instantaneously melts or softens the insert and adjacent portions of the members l and 2 so as to effectively weld them together.

As the button or insert is softened by thc welding current, the pressure tends to'force the two members l and 2 toward each other. Frequently it is desirable that the members l and 2 of the finished product should be spaced a predetermined distance apart; and my invention is especially advantageous in achieving this result. For this purpose, the insert is especially designed so that, in addition to its function as a welding element by the melting of a greater or smaller portion thereof, it shall also serve to space the members apart, which function implies a certain degree of solidit-y. One design of insert which harmonizes apparently contlicting requirements is illustrated in Fig. 5. In this design the button or insert may be considered as a disk with projecting shoulloo ders on its opposite 'faces 'The shoulders being of smaller area than the cross sectional area of the middle or 4disk portion .of the button or insert. In service these shoulders are Ain contact with the members to be welded and the heat eects are concentratedon them. 0n account of the disk being of greater areathan the shoulders, its eleciricalfresistance is less, and the portion of the disk out of alinement with the shoulders will remain comparatively cool during the very short interval required for the welding operation; and consequently this compara* tively cool portion will serve to limit the movement of the main members 1 and 2 and thus iX the permanent spacing thereof` 'lhe shape of the button or insert may bei` variously modified with a view to its service; as agspacing-member and divers forms arci shown in Fig. 7. The portion of the buttonl or insert notV in the direct path of the current tendsto'; protect the lbutton or insert from the eiiiects of too great concentration of the current. i

The invention is especially advantageousl l or the instantaneous welding together of! plates of diiierent thicknesses. @ther processes for such welding are either slow or liable to seriously impair the thinner plate in heating the thicker one to the Welding temperature, or are open to bot-h of these ob`i jections, and in some cases the welding cannot be done at all without previous prepa-i ration of the material. According to my invention,

the metal button or insert isy formed so that its area of contact with the thinner plate is larger than that with the thicker plate. The cone shaped butto-n illustrated at I in Fig. 7 suiiiciently illustrates this feature of the invention. By the use ot such a cone shaped button or insert, the electrict current, and consequently the heat ef` 'cct thereof.l are spread over a larger contact area of the thinner plate than on the thicker plate. It would bedesirable to so proportion the heated areas with reference tofthe other factors that the temperatures of the two plates at the point of contact with the insert should always bethe same; but as the pressure on the insert whlle soft modiies the contact area, it is impracticable Vto adhere to mechanical nicety of design. Broadly speaking, the area of the portion of the thinner plate in contact with the insert shouldl be larger than the like area of the thicker plate in inverse proportion to their thicknesses.

In most of the designs illustrated in Fig. 7, the insert has a bore extending entirely through it; but in other designs, one or both sides of the insert are hollowed out leaving an intermediate partition which will function as a spacing member. In the design illustrated at L in Fig. 7 the contact faces of the insert. are provided with projecting :inseam knobs or lugs spaced apart to secure the desired spread of the welding joint; Aand preferably the number and size of its knobs is such as to aggregate areas desired. All of these designs havethe-advantage of securing a Wide spreading joint for the comparatively crossy sectional area vof material. Amon lthe advantages of this wide spreading joint are an increase of rigidity and a larger area for the engagement of coperating parts.` 4

Among the principal advantages of my invention 1s its adaptability for joining members of different thicknesses, as abovega specified. Another important advantage is that the members to be welded require no preliminary treatment of any kind and consequently composite building structures of various types may be built up thereby out or'. ordinary commercial shapes. In com-y parison with the ordinary riveting process, wherein the members are weakened by the re- :noval of a portio-n of their metal, my process utilizes the full cross section of the ordinary commercial shapes used for members of the built up structure; in fact, t-he original cross section may be increased by the metal of the button. As the welding current is applied only where it is needed and as the inserts are easily positioned wherever theyv are wanted, the process is quite economical and very rapid. Another very important` advantage of the, process is that the wide range of variation inthe design of the insert gives the designer the greatest latitude in the building up of composite structures. This is especially true by reason of the facts that the welding may be effected at points which would be inaccessible, for riveting, and that an intermediate sheet or member may be welded to two other members on itsl opposite sides simultaneously. While I have shown the elements or members of the Iinished structure a's spacedapart a slight y distance, it is obvious that they may be pressed into contact with each other.

Obviously, the form oflbutton or insert and the various constructions hereinbefore mentioned admit of-many variations without departing Jfrom my invention.

What I claim is:

1. The process of joining metal elements which comprises the interposing of a metal insert between them and electrically welding the parts together simultaneously, the

`aggregate area vof the. contact portion of one face of the insert being less than the area inclosed in the contour of said face.

2. The process of joining metal elements which comprises the interposing of a metal insert between ing the parts together simultaneously, the portion of the insert in contact with one of the elements being` hollow.

3. r[he process of joining metal elements them .and electrically weld-A .ative position, against said insert, and welding the parts which comprises the interposing between them of a metal insert and electrically welding the parts together simultaneously, the

stantial alinement with said insert.

6. The process of joining metal elements so that in the resultin product they will be spaced a predetermined distance apart, which process consists in interposing a metal insert between said elements, adjusting said elements and insert` in desired relpressing said elements together oy an electric vcurrent applied to said elements, said insert being of such shape that a portion thereof will remain flrm `during the welding operation j and thereby serve to space said elements, and one face of the insert having a contact area less than the area of the contour of said face.

7. The process of electrically welding elementsv of different thicknesses which comprises the interposing of a metal insert be tween said elements at the point of welding, and then pressing the electrodes of the welding current against the outer surfaces of said elements, the insert being of such shape that the area of the portion thereof in contact with the thinner element is'larger than the area of the portion of said insert in contact with the thicker element, and one Contact face ofthe insert having a contact area less than the area of the contour of said face.

8. The process of electrically welding elements of diiierent thicknesses which coinprisesthe interposing of a metal insert between said elements at the point of welding, and then pressing the electrodes of the welding current against the outer surfaces of sald elements substantially in alinement with said insert, the insert being of such shape that the area of the portion thereof in contact with the thinner element is larger than the area of the portion of said insert in contact with the thicker element, and one contact face of the insert having a contact area less than the area of the contour of said face.

9. The process of electrically welding elements of diiierent thicknesses which comprises the interposing of a metal insert between said elements at the point of welding, and then pressing the electrodes of the welding current against the outer surfaces of said elements, the portion of the insert in contact with the thicker element being of smaller area than the cross-sectional area of the middle portion of said insert, and one contact face of the insert having a contact area less than the area of the contour of said face.

10. The process of joining metal elements which compi'ises the interposing of a metal insert between them and electrically welding the parts together simultaneously, the portion of the insert in contact with one of the elements being annular. 4

Signed at Buffalo, New York, this 2nd day of April, 1912.

ALBERT L. JOHNSON.

Witnesses: ARTHUR P. CLARK,

G. E. MALONEY. 

